As known, electrocardiography is a very useful tool to diagnose heart diseases, for example, arrhythmia, cardiac hypertrophy, myocardial infarction, coronary insufficiency, or angina pectoris.
Generally, the user can take the ECG examination in the hospital or at home. The ECG system used in the hospital provides comprehensive and accurate information with multi-lead (e.g., complete 12-lead) and/or long-term monitoring. On the other hand, the ECG Holter, which can be carried with the user, has a smaller volume for facilitating a 24-hour or longer ECG recording, this is particularly important for some diseases whose occurrences are unpredictable.
Afterward, a handheld ECG device is developed which is designed as compact and portable to perform a heart examination or ECG recording when needed. As using this kind of ECG device, the examination/recording can be easily performed by simply contacting the electrodes with the user's skin (hands and/or torso). Therefore, through this quick and convenient examination/recording, the user can check the heart situation due to the doctor's direction or the occurrence of uncomfortableness.
FIG. 1 shows a common handheld ECG device 100, including a main body 101, a display 102 and an operation interface 103. The main body 101 includes a first surface 1011 with a first electrode 104 mounted thereon and a second surface 1012 with a second electrode 105 mounted thereon. As using, after being switched on through the operation interface 103, the first electrode 104 should be contacted with the right hand of the user and the second electrode 105 should be contacted with the left hand or the torso at the left side. Then, by pressing the “START” button, the examination/recording starts lasting for a predetermined period of time. Finally, the result is shown on the display 102.
It is obvious that, as using the above-mentioned ECG device, the success of the examination/recording relies on the contact between the electrodes and the skin, that is, a certain level of force should be applied during the period to ensure a stable and workable contact. However, since the conventional ECG device does not indicate any relative information about the electrode contact or the force applied, the user might doubt that if a proper contact between the electrode and the skin is achieved. Accordingly, the user may question the accuracy of the result and further distrust it.
Therefore, for this kind of ECG device, it always happens that the user starts the examination/recording with an insufficient and/or unstable force application to cause an incorrect result, or the user, due to the fear of failure, nervously applies an excess level of force for achieving the contact so as to cause a mental stress or muscular pain.
Consequently, the object of the present invention is to provide a handheld ECG device which can provide the user a definite indication of the contact between the electrode and the skin during the examination/recording so as to increase the possibility of success.
Another object of the present invention is to provide a handheld ECG device which not only can remind the user if a proper contact for performing the examination/recording is achieved, but also can indicate the user the initiation, interruption and/or termination thereof, thereby contributing to the improvement of data accuracy and reliability.